Synthesis, characterization, and computational study of N‐protected amino acid inhibitors as well as assessment of corrosion resistance properties on mild steel in .5 M H2SO4 solution

Abstract

AbstractThe present article investigates the corrosion inhibition properties of N‐protected amino acids in .5 M H2SO4 solution on mild steel by gravimetric studies, potentiodynamic polarization method, and impedance spectroscopic techniques at different temperatures. This article evaluates synthetic methodology, characterization, and theoretical studies of N‐protected amino acid inhibitors with their anticorrosive property. Theoretical studies were conducted in the gaseous phase through a 6‐31 G (d, p) basis set from the B3LYP method. Potentiodynamic polarization studies revealed that both N‐protected amino acids behave as mixed‐type inhibitors. Impedance spectroscopic data confirmed the adsorption of the inhibitor on the metallic surface. Adsorption isotherm was employed to calculate the Gibbs free energy change. Langmuir adsorption isotherm is more acceptable for adsorption phenomena exhibited by the inhibitors. Thermodynamics and kinetic parameters of this adsorption phenomenon indicate that L2H was more efficient (94.13 ± .01% at .004 mol/L) than L1H (93.62 ± .02% at .004 mol/L) at 303 K. Surface morphology analysis of uninhibited and inhibited mild steel samples confirms that N‐protected amino acid inhibitors efficiently inhibit corrosion.